Antiseptic re-circulating toilet sump compositions



United States Patent 3,208,936 ANTISEPTIC RE-CIROULATING TOILET SUMPCOMPOSITIONS William F. Hamilton, Altadena, Califl, assignor to LockheedAircraft Corporation, Burbank, Calif. No Drawing. Filed Aug. 22, 1960,Ser. No. 50,865 2 Claims. (Cl. 252-1) This application is acontinuation-in-part of my copending application, Serial No. 700,755filed December 5, 1957 now Patent No. 2,998,390 issued August 29, 1961.This invention pertains to the disposal of human wastes in vehicles suchas aircraft, busses, trailers, boats, and the like, having chemicaltoilets where it is either dangerous, impractical or not possible tojettison the waste material which must consequently be stored forconvenient periodic disposition. Specifically, the object of thisinvention is to provide a fluid composition for the sump of a chemicaltoilet which will serve to abate odor, destroy bacteria, and which canbe used to flush residual waste matter from the sides of the toilet bowlor horn and simultaneously to provide a method of rapidly producinglarge volumes of foam stable during flushing operations.

The commonly used facility for human waste disposal consists of a toiletseat, a bowl or horn, and a receptacle or tank beneath for thecollection and storage of the deposits. It is conventional to charge thesump of such a toilet with a suitable amount of fluid for odor andbacterial control, but at the present time there is usually no provisionfor washing the waste matter from the bowl. This often causesobjectionable appearance and odor, and if the sump itself is visible, italso usually has a displeasing appearance.

Conventional sump fluid compositions vary widely, but they are almostalways water solutions or emulsions containing phenols or cresols,caustic soda or lime, chlorinated hydrocarbons, pine oil disinfectants,quaternary ammonium salts or soaps, covering or neutralizing aromatics,and/ or other materials selected from a wide variety of availablegermicides, perfumes and emulsifying agents. All of these compositionsbecome progressively more highly colored as wastes are added to them andare consequently not aesthetically suitable for recirculating flushingpurposes.

An improved mechanical type of toilet recently developed makes use of anelectrical pump to remove a portion of the sump fluid which is filteredand pumped around the toilet bowl horn flushing residual waste matterinto the sump. This development has rendered the appearance, stability,odor and germicidal qualities of the sump fluid even more important thanin the past.

THE COMPOSITION IN GENERAL As will be elaborated later on in moredetail, this in vention contemplates disinfectant sump compositionscontaining a foam agent which permits the emulsification of air in theliquid during flushing operations to give the fluid a clean, nearlywhite, soapy appearance. The fluid is left with a blanket of foam thatnot only improves its appearance but also assists in abatement of odors.The foaming agent may also have germicidal properties and act as agermicide in the composition.

This quality of the contemplated sump compositions goes a long waytowards solving the many problems inherent in obtaining a satisfactoryusable sump composition.

Nonetheless, this feature alone does not overcome all of theobjectionable features of conventional sump compositions that so greatlylimit their usefulness.

Another object of this invention is to produce a sump compositioncontaining a compatible mixture of several cooperating germicides foreffective sterilization of waste material; the contemplated germicidesare to include an antiseptic to attack bacteria and other microorganisms and one or a plurality of cooperating disinfectants forcontrol of disease germs and the like.

Another object of this invention is to provide the sump composition withsuitable odor masking and reodorizing agents.

Another object of this invention is to provide a disin fectant sumpcomposition having the above ingredients that is stable and active evenafter dilution with large amounts of waste material.

The instability of quaternary ammonium compounds and formaldehyde asgermicides in this invention, the additional foaming agent (if used) andthe dye (if used) in storage and during dilution with waste material isa major problem. In particular, the formaldehyde can attack thequaternary ammonium compounds, dye and foaming agent causingprecipitation of these constituents and rendering the compositionimpotent and unsightly after a period of storage or use. Thedesirability of using together the complementary germicides,formaldehyde and quaternary ammonium compounds, and the need toincorporate a foaming agent and a dye in the sump composition outweighthe consideration of omitting the formaldehyde if some way can be foundto make the ingredients compatible and still effective. The inventor has,discovered compositions which will meet these ends.

To further mask the appearance of the sump fluid, it has been founddesirable to add dyes to the sump composition to impart a pleasing colorto the sump fluid, masking the brown, red or amber colors thereof. Inthe past, dyes have been found to be either undesirable in appearance orunstable in the formaldehyde-quaternary ammonium compound-acidenvironment. The present invention also contemplates a suitable dyewhich is both compatible with the other ingredients of the compositionsand still pleasing in appearance even when diluted with waste material.

Metal corrosion in mechanical toilets is also a drawback to conventionalsump compositions. Due to the desirability of an acidic solution inmaintaining a stable composition, corrosion in excessive amounts is theresult. The corrosion is further accelerated by inherent corrosivequalities of the waste material. This invention also contemplates a sumpcomposition which contains a corrosion inhibitor which is bothcompatible with the other ingredients of the composition and effectiveeven when the composition has been diluted with large amounts ofcorrosive Waste material.

The compositions have been provided with an acid for buffering thesolution to a pH approximating 5 which will inhibit precipitation of theactive ingredients prior to and during dilution with waste material andat the same time remain almost completely noncorrosive to the metals inthe toilet structure including such light metals as aluminum andmagnesium-aluminum alloys so prevalently used in airplane structures.

There has previously been no easy way to ascertain whether the sumpfluid in a sump has received a charge of sump composition or to identifythe particular sump composition charged. Either chemical analysis orcompatible dye identification has been necessary. The latter methodproves unsatisfactory when the fluid is discolored by waste material andthe former obviously is too long and complicated to be of practical use.The presence of foam can reveal that a foaming agent has been added butgoes no further in identification of the sump composition in the sumpfluids. A normally colorless fluorescent 3 indicator dye which iscompatible with a masking dye is provided so that the presence of thesump composition may be detected by exposure to an ultra-violet lightsource.

It is to be noted that the sump compositions as outlined above willeconomically and effectively handle large amounts of waste material andare satisfactorily usable in both recirculating and sump type toilets.

METHOD OF USE FOR RE-CIRCULATION TYPE TOILETS The re-circulating pumpobviously produces a greater than atmospheric pressure on a fluid thatpasses through it. It follows therefore that any air entrained by ordissolved in the liquid is also subjected to this pressure. When thefluid emerges from the pump, this pressure is quickly relieved. Thissudden relief causes the entrained or dissolved air to expand rapidlythus producing large volumes of foam. It is necessary that large volumesof foam be rapidly produced upon ejection into the toilet bowl or hornso that a non-objectionable appearance is maintained at least for theperiod of the flushing operation. In aircraft, as will beobvious, theoutput of the pump must be sufficient to maintain proper circulation ofthe fluid at all cabin conditions as well as at sea level. Presentstandard operating equipment maintains a pumping pressure of about 12p.s.i. which is normally sufiicient to cause adequate foaming for thepurposes contemplated, without the necessity of adding bleed air toassist in the foaming.

However, bleed air may be used additionally whenever desired by additionof same to the intake of the pump or by entrapment during the flushingcycle.

QUATERNARY AMINES Several quaternary amines have been found suitable forthe purposes of this invention. The foremost of these are the1-(2-hydroxyethyl)2-n-alkyl-1 benzyl-2 imidazolinium chlorides.Preferably a mixture of these quaternary amines is used wherein then-alkyl groups are C C C and C hydrocarbon chains. A commercialpreparation of National Aluminate Corporation, Chicago, Illinois, knownas Nalquat G-81 1 (one of the aforementioned imidazolinium chlorides inwhich the n-alkyl group is derived from stripped coco fatty acids. Cocofatty acids contain the following acids aproximately: 3 to 9% oleic, lto 3% linoleic, /2 to 1 /2% capric, to 60% lauric, 17 to 27% myristic, 7to 15% palmitic, and 1 to 5% stearic) is such a mixture sixty percent inisopropanol solution.

Similarly, Nalquat G-8-12 (One of the aforementioned imidazoliniumchlorides in which the n-alkyl group is derived from approximately 39 to54% linoleic and 46 to 61% oleic acids) and Nalquat B8l3 (one of theaforementioned imidazolinium chlorides in which the nalkyl group isderived from oleic acid) may also be used although Nalquat G811 ispreferable due to its stability in the solution.

Nalquat G-8-12 is a mixture sixty percent in isopropanol solution of theabove quaternary imidazolinium salts in which the n-alkyl groups areheptadecenyl or heptadecadienyl hydrocarbon chains.

Nalquat G-8-13 is a sixty percent in isopropanol solution of the abovequaternary imidazolinium salt in which the n-alkyl group is theheptadecenyl hydrocarbon chain.

Soya trimethyl ammonium chloride marketed 50% in isopropanol solution asArquad S50 by Armour & Company, Chicago, Illinois, is another preferredquaternary amine. It may be used alone in the composition or morepreferably to supplement another quaternary amine such as the previouslydescribed Nalquat G8-11 for more thorough germicidal action, since noone germicide is equally effective against all types of bac- 4 teria.This is actually a mixture of amines having the formula CH3 R1\|T+ 7 0]CH3 \CH3 where R is mainly heptadecenyl and heptadecadienyl hydrocarbonchains and also with some heptadecatrienyl and saturated chains such asheptadecyl as R because the amines are derived from soya oil fattyacids.

FOAMING AGENTS The quaternary amines employed in the composition whichare discussed above also are significant foaming agents in a watersolution. However, in general they are insufficient alone in the smallquantities required for germicidal action to produce the desired foamingeffect in a sump composition for recirculating toilets. Besides beingtoo weak initially for this purpose, aging and dilution with wastematerial further emasculates their foaming capacity.

However, it has been found that a certain concentration of a mixture ofseveral quaternary amines in amounts necessary for proper germicidalaction impart sufficient foaming action to the composition without thenecessity of adding supplemental foaming agents. The amines previouslyidentified by the trade names Nalquat G-811 and Arquad S-50 addedtogether in appropriate quantities to the composition comprise thismixture.

It has been found that addition of a mixture ofl-(2-hydroxyethyl)-2-heptadecenyl-2 imidazoline and1-(2-hydroxyethyl)-2-heptadecadienyl-2 imidazoline in appropriateproportion to the compositions will impart the de sirable foamingcharacteristics for use in a re-circulating toilet regardless of thequaternary amine or amines employed. Preferably, a mixture of these twoamines in sixty percent weight concentration in isopropanol marketed asNalcamine G-l2 (one of the aforementioned imidazolines in which thealkyl group is derived from approximately 39 to 54% linoleic and 46 to61% oleic acids) by National Aluminate Corporation, Chicago, Illinois isused in the composition. The amount of foaming agent must be carefullyproportioned to give sufficient foam throughout the dilution cycle yetto avoid too much foam formation during circulation and flushing.

STABILIZERS Acetic and lactic acids have been discovered to beadvantageous and very useful as stabilizers for the composition,preventing the gradual loss of foaming ability upon dilution by wastematerial and aging of the composition. The acid further preventsreaction of the formaldehyde with the quaternary amines, a seriouslatent instability of the composition. Lactic acid is preferred due toits complete lack of obtrusive odor and extremely slight corrosiveness.

Cashmere in sufiicient quantities also adds to the stability of thecomposition.

CORROSION INHIBITOR Phosphate ion added to the composition, preferablyas a basic salt, such as di-sodium phosphate dedecahydrate has beenfound to inhibit corrosion of aluminum alloys and steel and to formphosphate protective coatings on the surfaces, thereof even afterdilution of the concentrate with large quantities of waste material.Thus any corrosiveness of the stabilizing acid of the composition or thewaste material is offset.

DYES

Although not a critical factor, it has been found advantageous to theappearance of the foaming composition to add a compatible organic dyethereto. Two dyes have been found particularly suitable, namely, MethylViolet and Alizarin Blue Sapphire G both of which are well known in theart.

TNDICATOR DYES The composition may contain a colorless indicator dyevisable only under ultraviolet light for purposes of indentification ofthe sump composition when in use in a re-circulating toilet. Presence ofthe dye indicates presence of a charge of sump composition in the sumpfluid. Beta Methyl Umbelliferone and Uranine (soluble fluorescein) havebeen found satisfactory and compatible in the composition. The formerdye fluoresces white under ultraviolet light and the latter yellowishwhite.

MASKING AGENT To mask or cover up the unpleasant sump odors an aromaticmaterial such as musk is added to the composition. The cashmere in thecomposition also serves this purpose.

For use in aircraft, it is essential that the weight of the sanitaryfacilities be minimized. The volume of the sump fluid must be as smallas possible and extra tanks such as separate reservoirs for flushingliquid must be eliminated.

SUMMARY In accordance with this invention, the sump acts as both wastestorage and flushing fluid reservoir and sump fluid serves to controlwaste odor, bacteria and appearance, as well as to operate acceptablyfor flushing purposes. In the proposed disinfectant sump compositions,the combination of agents for odor, bacterial control and for producingemulsified gaseous or air foam for control of the appearance makesadequate flushing and sanitation practical with a minimum of equipmentand waste.

Example I A preferred formulation for the flushable toilet compositionis:

To 150 ml. of water add and dissolve:

Nalquat 6-8-12 g 50 Acetic acid ml 50 Formaldehyde 40% ml 150 Oil ofcashmere ml 4 Oil of musk ml 2 Nalcamine G-l2 g 5 This charge is alittle less than one pint formulated for addition to three gallons ofsump water in an aircraft flushable toilet and is capable of dilution toat least twelve gallons with waste material without losing its foaming,germicidal and odor masking properties.

Observations were made of the sump composition in actual use in anaircraft re-circulating toilet mock-up during six days of operation. Thesump fluid was found to be only mildly corrosive to metal andnon-injurious to neoprene.

Bacteriological testing of the fluid after six days of operation showedno bacterial growth. Appearance and odor of the re-circulating fluid atthe end of the test was satisfactory.

When pumped through the filter from the sump, foam is generated in thecentrifugal pump and if illSllfl'lCiBIlt amount is produced bycavitation in the pump or if the fluid does not contain enough dissolvedgas for adequate foaming, bleed air is admitted into the suction line ofthe pump. The pressure drop across the pump has been found to be themost significant factor in the amount of foam produced and may be variedaccordingly to regulate to some degree the amount of foam produced. Thefoamed liquid from the pump circulated around the bowl or horn has awhite or very light creamy soapy appearance.

The quaternary ammonium salt in the composition must be at least 20 g.to be effective. Any increase in concentration over 70 g. does notappear to add to the germicidal effect of the composition.

The formaldehyde concentration may be varied from 20 ml. at whichconcentration it is faintly discernable, to about 200 ml. Muskconcentration should not be over 3 ml. as it imparts a slightlyunpleasant odor to the composition above this concentration. Oil ofcashmere may be used in a quantity of 1 ml. to quantities as high as 6ml. with satisfactory results. Its desirability is mainly due to itsincrease of foam stability and also to its reodorizing effect on thefluid.

Nalquat G-8-l2 may vary from 20 g. to 70 g. depending upon the amount fofoaming capacity desirable (this would vary with the type of toilet).

Acetic acid concentrations over 70 ml. are undesirable due to theincreasingly unpleasant sour odor imparted to the sump fluid. For properstability of the composition the amount should not fall below 20 ml.

The pint concentrate for the three gallon sump charge in the toilet,suitable for dilution to twelve gallons with waste matter shouldaccordingly contain approximately:

Water ml 20-250 Nalquat 6-8-12 g 20-70 Acetic acid g 20-70 Formaldehyde40% ml 20-200 Oil of cashmere ml 1-6 Oil of musk ml 0-3 Nalcamine G-l2 g2-10 Example II To 175 ml. of water add and dissolve:

Nalquat G-8-l2 g 50 Lactic acid 44% ml 25 Formaldehyde 40% ml Oil ofcashmere ml 2 Oil of musk ml 2 Nalcamine G-12 g 5 Uranine g 0.10

This pint charge is formulated for addition to three gallons of sumpWater in a re-circulating toilet and is capable of dilution to at leasttwelve gallons with waste material.

This. formulation varies from that of Example I only by the substitutionof lactic acid for acetic acid as stabilizer and a decrease in theamount of cashmere and formaldehyde. Uranine, a colorless fluorescingsubstance was also added for identification purposes.

The charge was tested in a mock-up aircraft toilet by a week of actualuse after dilution of the concentrate with three gallons of Water. Usersrecorded the odor to be mild to imperceptible and the foamy appearanceto be satisfactory.

Bacteria culture tests of samples of the sump fluids were all negative,all samples considered sterile. Samples were made directly of theflushing stream and the spray therefrom.

The sump fluid when viewed under ultraviolet light fiuoresced strongly.

The essential purpose of the lactic acid being to make the sump fluidacidic, the quantity may vary in the composition from 10 to 50 ml. of44% water solution of lactic acid. Corrosive action about the same asfor tap water was experienced during a two week test of the concentrateand the uesd sump fluid on various metals used in toilet construction.

Example Ill Alizarin Blue Sapphire G (0.5% H 0 solution) ml 18 Betamethyl umbelliferone (1% methanol solution) Example IV To 250 ml. ofwater add and dissolve:

Nalquat G-8-11 g 50 Arquad S-SO g 55 Lactic acid 44% ml 25 Formaldehyde40% ml 50 Oil of cashmere ml 4 Oil of musk ml 2 Methyl Violet g 0.095Disodi-um phosphate dodecahydrate g 45 The mixture is diluted toapproximately a pint charge. Tests in a re-circulating toilet werecarried out with addition of two ounces of the concentrate to fourgallons of sump water instead of the usual 16 ounce charge ofconcentrate. After 21 uses of the toilet over the period of one day nobreakdown in odor control was observed, indicating bacteriostasis since,when bacterial growth occurs, the odor control rapidly deteriorates. Oneday duration tests with four ounce charges achieved similar results.

Appearance during flushing was indicated as satisfactory by users. Whileless foam was obtained by this small charge, the fluid coloration by theblue dye supplemented the foam to give an appearance pleasing to theuser.

In the usual 16 oz. charge, foaming action is comparable to that foundin tests carried at for Examples I-III.

Corrosion tests of the concentrate and sump fluid diluted with wastematerial on various metals including aluminum alloys and various steelsshows much less corrosion occurs than with ordinary tap water.

Accelerated stability tests of the concentrate shows it to be stable forat least 1 and /3 years of storage at normal temperatures. Observationsshow no precipitation or insolubility and good color stability over thisperiod.

In this formulation no additional foaming agent is required due to thefoaming ability of Arquad S-SO and Nalquat G-8- 11 even at theselowconcentrations. Although t-he amounts of these quaternary amines maybe increased as desired, they should not be proportionately lower than20 g. Nalquat G-8-11 or 25 g. Arquad 8-50 for adequate bacteriostasisupon dilution with waste material in the sump.

Disodium phosphate may be omitted if desired since the treated sumpfluids are only very mildly corrosive without its addition. It may beadded up to as much as its solubility in the concentrate.

Due to the potency of this formulation and thus its consequentialgreater diluta-bility it is uniquely suitable as an economical allpurpose concentrate useable in both the sump type and re-circulatingtype toilets, particularly when there are shorter periods betweencleaning and servicing and thus no great safety margin is required.

It should be noted that the variations in the concentra: tions of theVarious ingredients discussed in Examples and II apply to theconcentration of the same ingredients in the remaining examples.

It is to be understood that the foregoing description is by way' ofillustration, and that changes, omissions, additions, substitutionsand/or modifications may be made Within the scope of the claims withoutdeparting from the spirit of the invention.

I claim:

1. An antiseptic sump composition for use in recirculating toilets fordilution with sump Water in a ratio of not less than A part compositionto 24 parts sump water which composition comprises:

(a) from about 20 to 250 ml. water (b) from about 20 to g. of anisopropanol solution of a quaternary amine, said amine being selectedfrom the group consisting of (1) 60% isopropanol solution of1-(2-hydroxyethyl) 2-n-alkyl-1 benzyl-Z-imidazolinium chloride in whichthe alkyl group is derived from an acid selected from the groupconsisting of (A) oleic acid (B) 39 to 54% linoleic acid and 46 to 61%oleic acid mixture (C) stripped coco fatty acids (2) 50% isopropanolsolution of soya trimethyl ammonium chloride (c) an acid selected fromthe group consisting of acetic and lactic in an amount to buffer saidcomposition to a pH of approximately 5 (d) from about 20 ml. to 200 ml.of 40% aqueous formaldehyde solution (e) from 0 to a color maskingpercentage of a masking dye selected from the group consisting of MethylViolet and Alizarin Blue Sapphire G.

(f) from 0 to a foam stabilizing amount during circulation of said sumpsolution of a foaming agent consisting of about a 60% isopropanolsolution containing a mixture of (1) 39 to 54% of1-(2-hydroxyethyl)-2-heptadeoenyl-2-imidazoline and (2) 46 to 61% of1-(2-hydroxyethyl)-2-hepta decadienyl-Z-imidazoline (g) from 0 to anindicating amount of an indicating dye selected from the groupconsisting of betal methyl umbelliferone and soluble fluorescein (h)from 0 to its solubility point in the concentrated solution of disodiumphosphate, and

(i) from '0 to an odor masking percentage of a odor masking agentselected from the group consisting of oil of cashmere and oil of musk.

2. The antiseptic sump composition of claim 1 in which:

(a) 10 to 50 ml. of 44% water solution of said lactic acid is present.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCESSoap and Chemical Specialties, February 1958, page 63.

JULIUS GREENWALD, Primary Examiner.

1. AN ANTISEPTIC SUMP COMPOSITION FOR USE IN RECIRCULATING TOILETS FORDILUTION WITH SUMP WATER IN A RATIO OF NOT LESS THAN 1/4 PARTCOMPOSITION TO 24 PARTS SUMP WATER WHICH COMPOSITION COMPRISES: (A) FROMABOUT 20 TO 250 ML. WATER (B) FROM ABOUT 20 TO 70 G. OF AN ISOPROPANOLSOLUTION OF A QUATERNARY AMINE, SAID AMINE BEING SELECTED FROM THE GROUPCONSISTING OF (1) 60% ISOPROPANOL SOLUTION OF 1-(2-HYDROXYETHYL)2-N-ALKYL-1 BENZYL-2-IMIDAZOLINIUM CHLORIDE IN WHICH THE ALKYL GROUP ISDERIVED FROM AN ACID SELECTED FROM THE GROUP CONSISTING OF (A) 100%OLEIC ACID (B) 39 TO 54% LINOLEIC ACID AND 46 TO 61% OLEIC ACID MIXTURE(C) STRIPPED COCO FATTY ACIDS (2) 50% ISOPROPANOL SOLUTION OF SOYATRIMETHYL AMMONIUM CHLORIDE (C) AN ACID SELECTED FROM THE GROUPCONSISTING OF ACETIC AND LACTIC IN AN AMOUNT TO BUFFER SAID COMPOSITIONTO A PH OF APPROXIMATELY 5 (D) FROM ABOUT 20 ML. TO 200 ML. OF 40%AQEUOUS FORMALDEHYDE SOLUTION (E) FROM 0 TO A COLOR MASKING PERCENTAGEOF A MASKING DYE SELECTED FROM THE GROUP CONSISTING OF METHYL VIOLET ANDALIZARIN BLUE SAPPHIRE G. (F) FROM 0 TO A FOAM STABILIZING AMOUNT DURINGCIRCULATION OF SAID SUMP SOLUTION OF A FOAMING AGENT CONSISTING OF ABOUTA 60% ISOPROPANOL SOLUTION CONTAINING A MIXTURE OF (1) 39 TO 54% OF1-(2-HYDROXYETHYL)-2-HEPTADECENYL-2-IMIDAZOLINE AND (2) 46 TO 61% OF1-(2-HYDROXYETHYL)-2-HEPTADECADIENYL-2-IMIDAZOLINE (G) FROM 0 TO ANINDICATING AMOUNT OF AN INDICATING DYE SELECTED FROM THE GROUPCONSISTING OF BETAL METHYL UMBELLIFERONE AND SOLUBLE FLUORESCEIN (H)FROM 0 TO ITS SOLUBILITY POINT IN THE CONCENTRATED SOLUTION OF DISODIUMPHOSPHATE, AND (I) FROM 0 TO AN ODOR MASKING PERCENTAGE OF A ODORMASKING AGENT SELECTED FROM THE GROUP CONSISTING OF OIL OF CASHMERE ANDOIL OF MUSK.